JP2008194847A - Mold for molding honeycomb structure and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for molding a honeycomb structure capable of more enhancing the compactness of a material immediately after extruded from a slit groove than before and capable of suppressing the occurrence of trouble such as a crack or the like in the honeycomb structure in the process after molding, and to provide its manufacturing method. <P>SOLUTION: The mold 8 for molding the honeycomb structure has a supply hole 81 for supplying a material and the slit groove 82 communicating with the supply hole 81 to be provided in a lattice form and molding the material into a honeycomb shape. The groove width W of the slit groove 82 becomes gradually narrow toward a groove forming surface 820 having the slit groove 82 formed thereto from the supply hole 81 and the angle α of inclination of the inner surface 821 of the slit groove 82 is 3'-5' with respect to the direction vertical to the groove forming surface 820. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a honeycomb structure forming mold for forming a honeycomb structure and a manufacturing method thereof.

  For example, a ceramic honeycomb structure used for an automobile exhaust gas purification filter or the like is formed by extruding a material containing a ceramic raw material using a honeycomb structure forming mold (hereinafter simply referred to as a mold). Manufactured by.

  As the mold, a mold having supply holes for supplying a material, and slit grooves for forming the material into a honeycomb shape, which is provided in a lattice shape in communication with the supply holes is used (Patent Document). 1 and 2). The slit grooves are generally formed with a constant groove width in the depth direction.

  However, when extrusion is performed using a mold having slit grooves with a constant groove width, the material tends to be thicker than the groove width of the slit grooves and extruded. This is considered to be because when the material is pushed out from the slit groove, the internal pressure is released due to the release of the atmospheric pressure, and the material expands slightly. For this reason, the formed honeycomb structure does not have sufficient density and has large pores, and accordingly, defects such as cracks occur during the steps such as drying and firing after forming. To do.

  For this reason, it is possible to improve the denseness of the material immediately after being extruded from the slit groove as compared with the prior art, and to cause defects such as cracks in the honeycomb structure in processes such as drying and firing after molding. A mold that can be suppressed is desired.

JP 2002-301581 A Japanese Patent Laid-Open No. 2003-11111

  The present invention has been made in view of such conventional problems, and can improve the denseness of the material immediately after being extruded from the slit groove as compared with the prior art. An object of the present invention is to provide a die for forming a honeycomb structure capable of suppressing the occurrence of defects and a method for manufacturing the same.

A first aspect of the present invention is a honeycomb structure molding die having a supply hole for supplying a material, and a slit groove provided in a lattice shape so as to communicate with the supply hole and for forming the material into a honeycomb shape. In
The groove width of the slit groove is gradually narrowed from the supply hole side toward the groove forming surface, and the inclination angle of the inner surface of the slit groove is 3 with respect to the direction perpendicular to the groove forming surface. The present invention provides a mold for forming a honeycomb structure, characterized in that it is '-5' (claim 1).

  In the mold for forming a honeycomb structure of the present invention, the slit groove has a groove width that is not constant, and is gradually narrowed from the supply hole side toward the groove forming surface. The inclination angle of the inner surface of the slit groove is 3 ′ to 5 ′ with respect to the direction perpendicular to the groove forming surface. That is, in the present invention, the slit groove has a groove width that is gradually narrowed in the direction in which the material is circulated, and the inclination angle is set to an angle in the specific range.

  By forming the slit groove in the above shape, when the material is extruded using the mold, the degree of compression can be gradually increased with respect to the material flowing in the slit groove. Therefore, it is possible to reduce the internal pores and improve the denseness. And since it extrudes in the state which raised the density sufficiently in that way, the swelling of the material immediately after extrusion becomes smaller than before. Therefore, the material can be formed into a honeycomb shape in a dense state higher than conventional.

  As a result, the honeycomb structure obtained by molding has few pores and has a sufficiently high density. And such a honeycomb structure can suppress generation | occurrence | production of malfunctions, such as a crack resulting from the pore etc. which exist in a material in subsequent processes, for example, processes, such as drying and baking.

  As described above, the honeycomb structure molding die of the present invention is configured such that the groove width of the slit groove is gradually narrowed in the specific direction, and the inclination angle is set to an angle in the specific range. The denseness of the material immediately after being extruded from the groove can be increased as compared with the conventional case, and it is possible to suppress the occurrence of defects such as cracks in the honeycomb structure in the post-molding process.

According to a second aspect of the present invention, there is provided a die for forming a honeycomb structure having a supply hole for supplying a material, and a slit groove provided in a lattice shape in communication with the supply hole and for forming the material into a honeycomb shape In the method of manufacturing
In machining the slit groove, high pressure water is jetted onto the groove forming position on the groove forming surface of the workpiece to form a water column, and a laser beam is irradiated through the water column to irradiate the laser beam. Perform an irradiation scan that moves the lens so that it passes a plurality of times along the groove forming position,
The irradiation scan is performed such that the groove width of the slit groove gradually decreases from the supply hole side toward the groove forming surface, and the inclination angle of the inner surface of the slit groove is perpendicular to the groove forming surface. In contrast, the method for manufacturing a honeycomb structure molding die is characterized in that the inclination of the water column is adjusted so as to be 3 'to 5' (claim 4).

  In the manufacturing method of the present invention, as described above, a groove is formed by a so-called water jet laser that forms a water column and irradiates a laser beam through the water column. In the irradiation scan, the groove width of the slit groove to be formed is gradually narrowed from the supply hole side toward the groove formation surface, and the inclination angle of the inner surface of the slit groove is the groove formation surface. It is performed while adjusting the inclination of the water column so that it becomes 3 ′ to 5 ′ with respect to the direction perpendicular to the vertical direction.

  As a result, the honeycomb structure molding die according to the first aspect of the present invention can be obtained in which the groove width of the slit groove is gradually narrowed in the specific direction, and the inclination angle thereof is an angle in the specific range. . And the said metal mold | die can improve the denseness of the material immediately after extruded from the said slit groove | channel conventionally, and can suppress that malfunctions, such as a crack, generate | occur | produce in a honeycomb structure in the process after a shaping | molding.

In the first invention, when the inclination angle of the inner surface of the slit groove is less than 3 ′ with respect to the direction perpendicular to the groove forming surface, the denseness of the material immediately after being extruded from the slit groove is increased. There is a possibility that it cannot be sufficiently increased than before. On the other hand, when the inclination angle exceeds 5 ′, the material density immediately after being extruded from the slit groove can be improved, but the resistance when extruding the material is increased, and formability and dimensional accuracy are increased. There arises a problem of a decrease in productivity and a decrease in productivity.
The angle 1 ′ corresponds to 1/60 of the angle 1 °. That is, 1 ° = 60 ′.

In the second aspect of the invention, when adjusting the inclination of the water column, an inclination adjustment fulcrum that is on the central axis of the water column and located on the groove forming surface or outward from the fulcrum is used as a fulcrum. It is preferable that the water column is inclined in a direction perpendicular to the moving direction of the laser irradiation position.
In this case, it is easy to form a slit groove having a configuration in which the groove width gradually decreases from the supply hole side toward the groove forming surface. Moreover, it becomes easy to provide a specific inclination angle on the inner surface of the slit groove.
Further, by setting the inclination of the water column to 3 ′ to 5 ′ with respect to the direction perpendicular to the groove forming surface, the slit groove intended in the present invention can be formed with high accuracy.

In the irradiation scan, it is preferable that the direction in which the water column is inclined is changed to the opposite side each time the laser irradiation position is passed once along the groove forming position.
In this case, it is possible to efficiently and accurately form a slit groove having a structure in which the groove width gradually decreases from the supply hole side toward the groove forming surface.

In the first and second aspects of the present invention, the groove width of the slit groove on the groove forming surface can be 40 to 150 μm (claims 2 and 7).
Even in the case of such a slit groove having a narrow groove width, the effect of enhancing the denseness of the material immediately after being extruded from the slit groove can be sufficiently exhibited.

The groove depth of the slit groove can be 2 to 3.5 mm (claims 3 and 8).
Even in the case of a slit groove having such a groove depth, the effect of enhancing the denseness of the material immediately after being extruded from the slit groove can be sufficiently exhibited.

Various shapes can be adopted as the shape of the slit groove according to the honeycomb structure to be formed. The lattice shape of the slit grooves can be, for example, a triangle, a quadrangle, a hexagon, or the like.
Further, as the material (workpiece) constituting the mold, metal materials, ceramics, and other various materials can be used. As the metal material, for example, SKD (alloy tool steel) can be used.

(Example 1)
DESCRIPTION OF THE PREFERRED EMBODIMENTS A honeycomb structure molding die according to an embodiment of the present invention and a manufacturing method thereof will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the honeycomb structure molding die 8 of the present example is provided in a lattice shape so as to communicate with the supply holes 81 for supplying the material and the supply holes 81, and the material is formed in a honeycomb shape. And a slit groove 82 for forming the film. The slit grooves 82 are provided in a rectangular lattice shape on the groove forming surface 820. In addition, the lattice shape of the slit groove | channel 82 can also be made into a triangle, a hexagon, etc., for example.

As shown in FIG. 3, the groove width W of the slit groove 82 gradually decreases from the supply hole 81 side toward the groove forming surface 820. The inclination angle α of the inner surface 821 of the slit groove 82 is 3 ′ to 5 ′ with respect to the direction perpendicular to the groove forming surface 820. The inclination angle α in this example is 4 ′. Further, the groove width W _{0 on} the groove forming surface 820 of the slit groove 82 is 90 μm, and the groove depth H is 2.5 mm.

Next, a method for manufacturing the honeycomb structure forming mold 8 will be described.
In manufacturing the mold 8, a groove processing apparatus 1 shown in FIG. 4 is used. The groove processing apparatus 1 forms a water column 72 by injecting high-pressure water around the laser beam 11 that generates the laser beam 71, the laser head 12 that derives the generated laser beam 71, and the laser beam 71. And a high-pressure water supply unit 14 for supplying high-pressure water for the water column 72 to the laser head 12. The laser head 12 and the nozzle portion 13 are integrally formed.
An optical fiber unit 21 is provided between the laser generator 11 and the laser head 12 to guide the laser beam 71 by connecting the two. A pipe 22 for supplying high-pressure water is provided between the high-pressure water supply unit 14 and the nozzle unit 13.

Further, as shown in the figure, the grooving apparatus 1 has a holding portion 19 that holds a workpiece (mold material 80 described later) and is movable in the XY axis direction. A drive unit (not shown) for moving the holding unit 19 is connected to the holding unit 19.
Moreover, this drive part, the high-pressure water supply part 14, and the laser generation part 11 are connected to the operation panel which is not illustrated for operating these.

A mold material 80 (FIG. 1), which is a material constituting the mold 8, is a rectangular metal plate having a length of 200 mm, a width of 200 mm, and a thickness of 15 mm. The mold material 80 is made of SKD61 (alloy tool steel). Of course, it is also possible to use a mold material having a different size and material.
In this example, the slit groove 82 is formed on the mold material 80 by using the groove processing apparatus 1. Further, in this example, before the slit groove 82 is processed, the supply hole 81 (FIG. 2) is provided in advance on the hole forming surface 810 of the mold material 80 using a drill.

And as shown in FIG. 1, the metal mold | die material 80 is set to the holding part 19 of the groove processing apparatus 1. As shown in FIG. Next, high pressure water is jetted from the nozzle portion 13 to the mold material 80 to form the water column 72, and the laser beam 71 is passed through the water column 72 to irradiate the mold material 80. Further, by moving the holding portion 19 in the X-Y axis direction, the laser irradiation position L for the mold material 80 is moved along the groove forming position, and an irradiation scan for passing the same groove forming position a plurality of times is performed.
At this time, the water pressure of the high-pressure water forming the water column 72 was 230 kgf / cm ² , and the pulse power of the laser beam 71 was 1400 W. The moving speed of the laser irradiation position L with respect to the mold material 80 was 150 to 240 mm / min, and the number of repetitions was 70 times.

  Further, in this example, during the irradiation scan, the groove width W of the slit groove 82 gradually decreases from the supply hole 81 side toward the groove forming surface 820, and the inner surface 821 of the slit groove 82 is inclined. The inclination of the water column 72 to be formed was adjusted so that the angle α was 4 ′ with respect to the direction perpendicular to the groove forming surface 820.

Specifically, as shown in FIGS. 5A and 5B, the direction in which the water column 72 is formed is changed by changing the direction of the nozzle portion 13. At this time, the inclination of the water column 72 is determined by moving the water column 72 in the moving direction of the laser irradiation position L (perpendicular to the paper surface) with an inclination adjustment fulcrum 722 as an intersection of the central axis 721 of the water column 72 and the groove forming surface 820. ) With respect to the vertical directions P ₁ and P ₂ .

Further, in this example, each time the laser irradiation position L is passed along the groove forming position, the direction in which the water column 72 is inclined is changed to the P ₁ direction (FIG. 5A) and the P ₂ direction (FIG. 5B). ) Alternately. The inclination β of the water column 72 is 4 ′ with respect to the direction perpendicular to the groove forming surface 820. In FIGS. 5A and 5B, a region where the slit groove 82 is finally formed is indicated by a dotted line.

As a result, as shown in FIG. 3, the groove width W _{0 on} the groove forming surface 820 is 90 μm, the groove depth H is 2.5 mm, and the groove width W gradually increases from the supply hole 81 side toward the groove forming surface 820. A slit groove 82 that is narrow and has an inclination angle α of the inner surface 821 of 4 ′ with respect to the direction perpendicular to the groove forming surface 820 was obtained.
Thus, a honeycomb structure molding die 8 was produced.

Next, the function and effect of the honeycomb structure forming mold 8 of this example will be described.
In the mold 8 of this example, the slit groove 82 has a groove width W that is not constant, and is gradually narrowed from the supply hole 81 side toward the groove forming surface 820. The inclination angle α of the inner surface 821 of the slit groove 82 is 3 ′ to 5 ′ with respect to the direction perpendicular to the groove forming surface 820. In other words, in this example, the slit groove 82 gradually narrows the groove width W in the direction in which the material flows, and the inclination angle α is set to an angle in the specific range.

  By making the slit groove 82 in the above shape, when the material is extruded using the mold 8, the degree of compression can be gradually increased with respect to the material flowing in the slit groove 82. Therefore, it is possible to reduce the internal pores and improve the denseness. And since it extrudes in the state which raised the density sufficiently in that way, the swelling of the material immediately after extrusion becomes smaller than before. Therefore, the material can be formed into a honeycomb shape in a dense state higher than conventional.

  As a result, the honeycomb structure obtained by molding has few pores and has a sufficiently high density. And such a honeycomb structure can suppress generation | occurrence | production of malfunctions, such as a crack resulting from the pore etc. which exist in a material in subsequent processes, for example, processes, such as drying and baking.

  Thus, in the honeycomb structure molding die 8 of this example, the groove width W of the slit groove 82 is gradually narrowed in the specific direction, and the inclination angle α is set to an angle in the specific range. The denseness of the material immediately after being extruded from the slit groove 82 can be improved as compared with the conventional case. And it can suppress that malfunctions, such as a crack, generate | occur | produce in a honeycomb structure in the process after shaping | molding.

(Example 2)
In this example, a honeycomb structure was actually formed using the honeycomb structure forming mold 8 of Example 1 and evaluated.

In this example, the honeycomb structure molding die 8 of the first embodiment (product of the present invention) was used to extrude a clay-like ceramic material so that it was surrounded by the cell walls 61 as shown in FIG. A honeycomb structure 6 having a large number of cells 62 and a cylindrical outer peripheral wall 63 covering the outer peripheral side surface was formed. As the ceramic material, a cordierite raw material kneaded with water, a binder or the like was used. Then, the formed honeycomb structure 6 was left in air with a humidity of 60%, and the occurrence of defects such as cracks was observed.
For comparison, a conventional mold for forming a honeycomb structure (comparative product) having slit grooves with a constant groove width was prepared, the honeycomb structure was similarly molded, and the same evaluation was performed.

Next, the evaluation result will be described.
As shown in FIG. 7B, the honeycomb structure formed using the comparative product showed cracks in the outer peripheral wall portion in about 1 minute after being left standing. On the other hand, as shown in FIG. 7 (a), the honeycomb structure formed using the product of the present invention did not show any cracks or the like even after 4 minutes had passed after being left.

  Thus, from the above results, it can be seen that the honeycomb structure forming die 8 of the present invention product can improve the denseness of the material immediately after being extruded from the slit groove 82 as compared with the conventional one. . And it turns out that the honeycomb structure 6 obtained by shaping | molding has few internal pores, becomes a thing with sufficient denseness, and can suppress generation | occurrence | production of defects, such as a crack, after shaping | molding.

(A) Explanatory drawing which shows the groove formation surface of the honeycomb structure shaping | molding die in Example 1, (b) The expansion explanatory drawing of a groove formation surface. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. Expansion explanatory drawing around a slit groove in Example 1 BRIEF DESCRIPTION OF THE DRAWINGS FIG. Explanatory drawing which shows a mode that the formation direction of the water column in (a) and (b) in Example 1 is adjusted. FIG. 6 is an explanatory view showing a honeycomb structure in Example 2. Explanatory drawing which shows the mode of the external appearance of (a), (b) honeycomb structure in Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Groove processing apparatus 6 Honeycomb structure 61 Cell wall 62 Cell 63 Outer peripheral wall 8 Honeycomb structure shaping | molding die 81 Supply hole 82 Slit groove 820 Groove formation surface 821 Inner surface

Claims (8)

In a honeycomb structure molding die having a supply hole for supplying a material and a slit groove provided in a lattice shape in communication with the supply hole, and forming the material into a honeycomb shape,
The groove width of the slit groove is gradually narrowed from the supply hole side toward the groove forming surface, and the inclination angle of the inner surface of the slit groove is 3 with respect to the direction perpendicular to the groove forming surface. A die for forming a honeycomb structure, characterized by being '-5'.   2. The honeycomb structure molding die according to claim 1, wherein a groove width of the slit groove on the groove forming surface is 40 to 150 [mu] m.   3. The mold for forming a honeycomb structure according to claim 1, wherein a depth of the slit groove is 2 to 3.5 mm. In a method for manufacturing a honeycomb structure forming die having a supply hole for supplying a material and a slit groove provided in a lattice shape in communication with the supply hole, and forming the material into a honeycomb shape,
In machining the slit groove, high pressure water is jetted onto the groove forming position on the groove forming surface of the workpiece to form a water column, and a laser beam is irradiated through the water column to irradiate the laser beam. Perform an irradiation scan that moves the lens so that it passes a plurality of times along the groove forming position,
The irradiation scan is performed such that the groove width of the slit groove gradually decreases from the supply hole side toward the groove forming surface, and the inclination angle of the inner surface of the slit groove is perpendicular to the groove forming surface. The method for manufacturing a honeycomb structure forming die, wherein the water column inclination is adjusted so as to be 3 'to 5'.   In claim 4, when adjusting the inclination of the water column, the water column is located on the center axis of the water column and the tilt adjustment fulcrum located on the groove forming surface or outward from the fulcrum. A method for manufacturing a mold for forming a honeycomb structure, wherein the mold is tilted in a direction perpendicular to a moving direction of a laser irradiation position.   6. The honeycomb structure forming metal according to claim 5, wherein, in the irradiation scan, the direction in which the water column is inclined is changed to the opposite side each time the laser irradiation position is passed once along the groove forming position. Mold manufacturing method.   The method for manufacturing a honeycomb structure forming die according to any one of claims 4 to 6, wherein a groove width of the slit groove on the groove forming surface is 40 to 150 µm.   The method for manufacturing a honeycomb structure molding die according to any one of claims 4 to 7, wherein a groove depth of the slit groove is 2 to 3.5 mm.